title: Arthroscopic evaluation of trochlear dysplasia as an aid in decision making for the treatment of patellofemoral instability.
abstract: OBJECTIVE
  Trochlear dysplasia is an important aetiological factor for the development of patellofemoral instability (PFI). The aim of the study was to identify the arthroscopic morphology of trochlear dysplasia that can be helpful when planning operative treatment for PFI.
  
  
  METHODS
  Magnetic resonance imaging (MRI) scans and strict lateral radiographs of 46 patients treated for PFI were assigned according to Dejour and matched with arthroscopic views from the lateral superior arthroscopic portal. On arthroscopy, signs of trochlear dysplasia were identified and classified into two types. Intra- and inter-observer agreements of the arthroscopic evaluation were assessed.
  
  
  RESULTS
  Arthroscopically, 2 major types of trochlear dysplasia could be distinguished. Type I shows a flat trochlear groove with an elevated trochlear floor in relation to the anterior femoral cortex. In type II, the proximal trochlea was convex with a lateral trochlear bump. Arthroscopic evaluation was not consistent with the Dejour's radiographic and axial MRI classification. Arthroscopic grading showed excellent intra- and inter-observer agreements (81-92%).
  
  
  CONCLUSIONS
  Arthroscopic evaluation can give additional information about the severity of trochlear dysplasia. This additional information can be used as an aid in decision making for the treatment of PFI.
  
  
  METHODS
  II.
authors.affiliation: Orthopaedic Specialty Clinic, Clinics Kempten/Oberallgäu, MVZ Oberstdorf, Trettachstrasse 16, 87561, Oberstdorf, Germany, manfred.nelitz@mvz-oberstdorf.de.
authors.forename: M
authors.initials: M
authors.lastname: Nelitz
authors.forename: S
authors.initials: S
authors.lastname: Lippacher
mesh_terms: D000293:Adolescent; D000328:Adult; D001182:Arthroscopy; D005260:Female; D005269:Femur / Q000002:abnormalities / Q000473:pathology / Q000601:surgery*; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D057071:Patellofemoral Joint / Q000601:surgery; D012189:Retrospective Studies; D055815:Young Adult